Fuel from water and carbon dioxide

The German carmaker Audi has begun producing synthetic diesel fuel from water and carbon dioxide in Dresden. This diesel fuel is "green" on many levels, as the CO₂ for the process comes from biogas and the electricity for water electrolysis also comes from "clean" sources.

The technology involves the electrolysis of water into hydrogen and oxygen at a temperature of XNUMX degrees Celsius. According to Audi and its partner, this stage is much more efficient than the electrolytic methods known so far, since part of the thermal energy is utilized. At the next stage, in special reactors, hydrogen reacts with carbon dioxide under high pressure and high temperature. A long chain hydrocarbon fuel called "Blue Crude Oil" is produced.

According to the manufacturer, the efficiency of the transition process from renewable electricity to liquid fuels is 70%. Blue Crude then undergoes refining processes similar to crude oil to produce diesel fuel ready for use in engines. According to tests, it is very pure, can be mixed with traditional diesel fuel and will soon be able to be used separately.